We have found that if a physical barrier is provided within the teat canal and/or the lower teat sinus during the dry period without the use of antibiotics, the incidence of mammary disorders is substantially reduced. This is very surprising as all conventional treatments involve the use of antibiotics. Because no antibiotics are required very substantial advantages result, without any significant reduction in effectiveness.
According to the invention there is provided an antiinfective-free formulation for prophylaxis of intramammary infection comprising a seal formulation to provide a physical barrier in the teat canal.
This non-antibiotic approach to preventing new dry period infection in dairy cows has major potential for the dairy industry as it results in the reduction of the incidence of antibiotic contamination in early season milk production. Thus the invention provides a quality improvement to dairy production and will facilitate farmers meeting consumer preferences for reducing the level of antibiotics used in food production.
According to another aspect the invention provides an antiinfective-free method of prophylactic treatment of mammary disorders in non-human animals during an animals"" dry period by sealing the teat canal with a seal formulation to provide a physical barrier in the teat canal.
The invention also provides a prophylactic method of controlling the infection of the mammary gland by a mastitis-causing organism by sealing the gland with a seal formulation to provide a physical barrier in the teat canal.
In a particularly preferred embodiment of the invention the seal formulation comprises a non-toxic heavy metal salt in a gel base. Preferably, the heavy metal salt is present in an amount of between 50% and 75% by weight, most preferably approximately 65% by weight. We have found that these are the optimum levels of heavy metal salt to achieve an effective seal.
In a preferred embodiment of the invention the heavy metal salt is bismuth sub-nitrate. This is a particularly useful non-toxic heavy metal salt.
In one embodiment of the invention the base is a gel based on aluminum stearate. Preferably, in this case, the gel includes a vehicle such as liquid paraffin. This formulation has effective processing and use properties.
In another embodiment of the invention the gel comprises a polyethylene gel. The gel may be based on low density polyethylene or on high density polyethylene.
The invention also provides a veterinary composition for use in the prophylactic treatment of mammary disorders in non-human animals during an animals"" dry period.
According to a further aspect the invention provides a process for preparing a seal formulation comprising the steps of adding a non-toxic heavy metal salt to a gel base in at least two separate stages. This process is particularly effective for producing the preferred seal formulation of the invention.
Preferably, a first portion of heavy metal salt is added to a gel base in a first stage and a second portion of the heavy metal salt is added to the gel base containing the first portion of the heavy metal salt.
In this case preferably the weight ratio of the second portion of the heavy metal salt to the first portion of the heavy metal salt is at least 1:1, most preferably approximately 2:1.
The invention will be more clearly understood from the following description thereof given by way of example only.